mark wragg/Thinkstock(NEW YORK) -- Older women with a strong family history of breast cancer might soon have a new, safer option to help them avoid developing the disease.

New research led by Dr. Jack Cuzick, head of the Cancer Research the U.K.’s Center for Cancer Prevention, looked at a drug called anastrozole, a therapy already used to stave off breast cancer recurrence in postmenopausal women who have experienced the disease.

Among the questions Cuzick and his team hoped to answer was whether the same therapy could help prevent breast cancer in women who never had the disease but have a high risk of developing it.

To answer this question, they studied more than 3,800 women in 18 countries who had a strong family history of the disease -- at least two relatives with breast cancer, for example, or women whose mother or sister developed the disease at a young age.

The researchers found that a daily anastrazole pill cut breast cancer incidence in these women by more than half -- 53 percent -- with few side effects.

“The biggest surprise of our study was that the side effects were less than expected,” Cuzick said.

Cuzick presented the new study Wednesday at the San Antonio Breast Cancer Symposium. The study also appears in the journal Lancet.

This would not be the first drug to be used to prevent breast cancer in women who have a high risk of the disease; a small number of women take drugs like tamoxifen and raloxifene for this purpose. But their side effects, which include an elevated risk for blood clots, stroke and other cancers, keep many women away from such treatments.

While anastrazole is not without its side effects, the hot flashes and joint pain that accompany its use are generally considered to be less severe than other more serious issues.

Doctors not involved with the study said the findings were promising. Dr. Angel Rodriguez, a breast cancer doctor at Houston’s Methodist Cancer Center, said that based on this study, he will start using the drug for this purpose in his patients.

“We need to raise awareness that medications to prevent cancer exist,” Rodriguez said. “It is vastly underutilized in the world. This study further validates their safety -- a major concern for most prescribers.”

Dr. Lawrence Wickerham, chief of cancer genetics and prevention at Allegheny General Hospital in Pittsburgh, agreed that the finding could change clinical practice.

“The results will provide an additional option for postmenopausal women to decrease their risk of developing breast cancer,” he said.

Not all doctors agreed, however, that all women who could potentially benefit from this treatment would be willing to endure the side effects of the drug.

“Asking women to take a daily pill to prevent breast cancer is a hard sell, particularly when there is an undertow of other concerns that arise with taking the pill,” said Dr. Michael Fisch, chair of medical oncology at the University of Texas MD Anderson Cancer Center in Houston.